Fix run line

llvm-svn: 39401
diff --git a/clang/test/Preprocessor/cxx_true.cpp b/clang/test/Preprocessor/cxx_true.cpp
index f20d8cf..5ebdaf8 100644
--- a/clang/test/Preprocessor/cxx_true.cpp
+++ b/clang/test/Preprocessor/cxx_true.cpp
@@ -1,6 +1,6 @@
-/* RUN: clang -E t.cpp -x=c++ | grep block_1 &&
-   RUN: clang -E t.cpp -x=c++ | not grep block_2 &&
-   RUN: clang -E t.cpp -x=c | not grep block
+/* RUN: clang -E %s -x=c++ | grep block_1 &&
+   RUN: clang -E %s -x=c++ | not grep block_2 &&
+   RUN: clang -E %s -x=c | not grep block
 */
 
 #if true